Conventionally, there are image forming apparatuses to which application programs can be added as plug-ins after shipment. For example, applications developed in C language (hereinafter, “C applications”) and applications developed in Java (registered trademark) (hereinafter, “J applications”) can be installed in the image forming apparatus described in patent document 1.
However, the platform for C applications and the platform for J applications are different. Specifically, the platform for J applications is formed by providing, on a platform for C applications, a platform provided with API (Application Program Interface) for Java (registered trademark) (the JSDK platform in patent document 1).
The model dependence of the JSDK platform is significantly lower than that of the platform for C applications. That is to say, the API of the JSDK platform is leveled out to be applicable to various model types. From the viewpoint of the developer of applications, it is more advantageous to develop applications as J applications. This is because in the case of J applications, the necessity of changing source codes for respective model types is low, and therefore development costs can be reduced.
However, the function range of API provided by JSDK platforms is narrower than that of platforms for C applications. That is to say, the number of functions that can be implemented by genuine J applications is less than that of genuine C applications. A genuine J application means a J application that is configured with only program modules that operate on a JSDK platform.
Thus, if a function cannot be implemented only by a J application, the function needs to be installed as a C application. In this case, a package including both a J application module and a C application module is sold as one application.
An application including both a J application and a C application may appear to be a single application to the user, but this application is perceived as two applications by an image forming apparatus that cannot recognize an application having such a configuration (i.e., a configuration including both a J application and a C application). Thus, the user needs to perform an install operation two times (the user needs to give an instruction to execute an install operation two times).
In such an image forming apparatus, by correcting the install mechanism of applications in consideration of applications having the above configuration, it is technically possible to execute both a process of installing a J application and a process of installing a C application by a single install instruction.
However, image forming apparatuses that cannot recognize an application including both a J application and a C application are already vastly commercially available and are being used by end users. It would require large amounts of cost and work to apply the above-described corrections to these image forming apparatuses.    Patent Document 1: Japanese Laid-Open Patent Application No. 2007-49677